Modelling and Extremum Seeking Control of a Cascade of Two Anaerobic Bioreactors

The principle of extremum seeking control has been applied on a cascade of two anaerobic bioreactors using the dilution rate as control action and the biogas flow rates as measured outputs to be maximized. In all cases maximum biogas flow rate with sensible decrease of the general output depollution parameter (compared to the case of one single bioreactor) has been obtained, starting from different initial conditions. With the same algorithm, good performances have been obtained in the presence of variations of the inlet organics. Its implication for biotechnology may result in substantial economic benefits.